The rules do not say 1 class
Not addressed in this class document.
- Runabout Rec Lites · RRL
IJSBA · Engine
Aftermarket valve springs and retainers, IJSBA
Often the only cylinder-head part legal in a stock class.
This page is IJSBA only, and the bodies do not agree. The same part under IHRA and UIM. Which one applies to you is decided by whoever sanctions the race you enter.
Where it stands, class by class
14 classes, grouped where the same rule gives the same answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules.
What each answer below means
- The rules do not say
- Unanswered. The rules do not settle this, so ask the club before you rely on it.
- Legal, with conditions
- Keep it, but measure it: the rules permit this part only inside stated limits.
- Legal
- Keep it. The rules permit this part in this class.
Legal, with conditions 1 class
IJSBA-approved valves, valve springs and retainers. Conflicts with the OEM weight and dimension rule elsewhere in the document, and which one governs is not settled.
- Four Stroke Ski Lites · FSKL
Legal, with conditions 1 class
Listed as allowed in one place and as requiring IJSBA approval per RNA.3.9 in another, and which one governs is not settled.
Legal, with conditions 1 class
Aftermarket springs and retainers in the 0-1100cc category ONLY. In 1101-1500cc, springs and retainers must be OEM. · SKM.4.5
Legal, with conditions 1 class
Aftermarket retainers with OEM springs; valves, seats, springs and pushrods may be modified or aftermarket. Titanium prohibited unless originally equipped.
- Runabout Limited · RAL
Legal, with conditions 1 class
Titanium valves, pushrods and seats prohibited unless originally equipped. · RSS.3.10, RSS.3.12
Legal 5 classes
Aftermarket valvetrain components, valve springs and retainers included, are allowed provided the original method of valve activation is kept.
- Ski Superstock · SKSS.3.3
- Freestyle · FREST.7.3
- Ski Grand Prix · SKGP.6.3, SKGP.7.3
- Sport GP · SPGP.4.3
- Runabout Open / GP · ROP.4.3
Legal 2 classes
Valve springs and valve spring retainers allowed; replacement valves and seats at OEM weights and dimensions.
- Fixed Steering Ski Stock · FSSK.3.4, FSSK.3.8
- Ski Stock · SSK
Legal 1 class
Aftermarket valve springs and valve spring retainers may be used. A later clause in the same four-stroke section allows them only when IJSBA approved. · RAS.3.5, RAS.3.9
Aftermarket valve springs and retainers: if the rule your class applies reads differently to you, or the rulebook has changed since this was read, ask. We answer with the section we read it from, or that we have not read it. Ask a rules question.
Every IJSBA class · where the rulebooks differ · checks on parts the shop sells · how this site reads a rulebook.
Engine · four stroke · legal in 13 of 14 answered, 5 with conditions